polyfill fetch globals on nodeapi

package-lock.json

@@ -108,6 +108,15 @@
       "integrity": "sha512-VRQB+Q0L3YZWs45uRdpN9oWr82meL/8TrJ6faoKT5tp0uub2l/aRMhtm5fo68h7kjYKH60f9/bay1nF7ZpTW5g==",
       "dev": true
     },
+    "@types/node-fetch": {
+      "version": "1.6.9",
+      "resolved": "https://registry.npmjs.org/@types/node-fetch/-/node-fetch-1.6.9.tgz",
+      "integrity": "sha512-n2r6WLoY7+uuPT7pnEtKJCmPUGyJ+cbyBR8Avnu4+m1nzz7DwBVuyIvvlBzCZ/nrpC7rIgb3D6pNavL7rFEa9g==",
+      "dev": true,
+      "requires": {
+        "@types/node": "8.0.19"
+      }
+    },
     "@types/node-forge": {
       "version": "0.7.1",
       "resolved": "https://registry.npmjs.org/@types/node-forge/-/node-forge-0.7.1.tgz",

package.json

@@ -28,15 +28,16 @@
     "@types/keytar": "^4.0.1",
     "@types/lunr": "2.1.5",
     "@types/node": "8.0.19",
+    "@types/node-fetch": "^1.6.9",
     "@types/node-forge": "0.7.1",
     "@types/papaparse": "4.1.31",
     "@types/webcrypto": "0.0.28",
     "concurrently": "3.5.1",
     "electron": "1.8.4",
     "jasmine": "^3.1.0",
-    "jasmine-ts-console-reporter": "^3.1.1",
     "jasmine-core": "^2.8.0",
     "jasmine-spec-reporter": "^4.2.1",
+    "jasmine-ts-console-reporter": "^3.1.1",
     "karma": "^1.7.1",
     "karma-chrome-launcher": "^2.2.0",
     "karma-cli": "^1.0.1",

src/services/nodeApi.service.ts

@@ -1,11 +1,14 @@
-import { Utils } from '../misc/utils';
+import * as fe from 'node-fetch';
 
 import { ApiService } from './api.service';
 
 import { PlatformUtilsService } from '../abstractions/platformUtils.service';
 import { TokenService } from '../abstractions/token.service';
 
-import * as fetch from 'node-fetch';
+(global as any).fetch = fe.default;
+(global as any).Request = fe.Request;
+(global as any).Response = fe.Response;
+(global as any).Headers = fe.Headers;
 
 export class NodeApiService extends ApiService {
     constructor(tokenService: TokenService, platformUtilsService: PlatformUtilsService,